Alejandro Moreno and Ross Dyer discuss the winners and losers of the Alexis Sanchez saga.

MANCHESTER -- Arsenal's problems in the transfer market and the stagnation within Arsene Wenger's squad have been further highlighted by a summer transfer review launched at Manchester's Soccerex conference.

Despite laying out Europe's sixth-highest fee to Lyon in paying €53 million for Alexandre Lacazette, Arsenal closed the transfer window as only the ninth biggest spenders in the Premier League, behind eighth-placed Leicester and seventh-placed Watford. Arsenal collected €69m from sales of players including Alex Oxlade-Chamberlain to Liverpool, Kieran Gibbs to West Brom and Gabriel Paulista to Valencia.

With their only other senior signing being Sead Kolasinac, on a free transfer from Schalke, Arsenal did not pay out another fee, with their €101m final-day bid for Monaco's Thomas Lemar reportedly failing because the winger did not want to play in the Europa League. Monaco had already collected the most money in one transfer window in history, having sold players for €358m, including Kylian Mbappe to Paris Saint-Germain, Tiemoue Bakayoko to Chelsea and Bernardo Silva and Bernard Mendy to Manchester City.

Meanwhile, Wenger's problems in refreshing his squad are highlighted by Arsenal players having the Premier League's longest average stay at the club, 3.8 years, compared to second-placed Manchester United's 3.2 years. Liverpool, who finished a place above Arsenal last season to steal fourth place and Champions League football, kept their players for an average of 2.2 years.

Wenger has suffered the extra headache of players seeing out contracts, with both Alexis Sanchez and Mesut Ozil, in their final years, able to agree deals with new clubs from Jan. 1. Oxlade-Chamberlain was in a similar situation before his move to Anfield on deadline day.

Arsenal boss Arsene Wenger has faced criticism over his transfer dealings this summer.

Esteve Calzado, former chief marketing and commercial officer for Barcelona and an advisor for City, said, as he launched the report compiled for Prime Time Sport: "I think we should analyse each case separately, and I don't think this comes from a specific strategy that has got them in this situation, because they are not stupid because they have been trying to renew Sanchez, Ozil and Oxlade-Chamberlain for a long time.

"The key question, I think, is how successful the team is on the pitch, because good players want to be in teams that compete for the trophies and play Champions League."

Arsenal retain the highest number of homegrown players in their squad with six, ahead of Southampton on five and United on four. City have just one, while Swansea, Bournemouth and Burnley have no youth products in their squads.

The summer transfer window, which closed on Thursday in England and Friday on Spain, broke spending records across Europe's top five leagues, climbing 16 percent on the previous year from €3.235 billion to €4.392bn.

PSG's expenditure on Neymar, who cost €222m, and Mbappe, officially loaned from Monaco but whose price is set for €180m next summer, meant they alone spent €418m, considerably more than City, ranked second on €244m.

Calzado said: "We have seen five transactions that have joined the historic top 10. Last year, when transfers reached €100m [when United paid €105m to Juventus for Paul Pogba] we were very shocked by the number. Who would have thought the number would just double and that number would be doubled twice?"

The Premier League remained Europe's highest spending league, lavishing €1.572bn on players this summer, up 16 percent on last year, while PSG's dealings raised Ligue 1 to second place on €853m, a rise of 449 percent.

John Brewin is a staff writer for ESPN FC. Follow him on Twitter @JohnBrewinESPN.